Braces for dentifacial functional orthopaedic and periodontal treatment

ABSTRACT

Braces for dentifacial functional orthopaedic and periodontal treatment made of natural or synthetic, flexible, food-grade material, generally consisting of a double cradle (or trough), these two cradles having externally, in a plane, a flaring U-shape and separated by a thick horizontal partition (3). The braces are further characterised in that: (a) the portion of the cradle designed for receiving the lower incisors is sufficient for fitting in the lower four incisors; (c) the height of the side lingual (2) and vestibular (1) partitions defining the channel designed for receiving the lower incisors (4), from the thick horizontal partition (3), is at least equal to the height of the incisors up to their neck.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject of the present invention is medical appliances forfunctional dento-facial orthopaedic treatment and periodontics, aimed atcorrecting functional disorders with neurovegetative functions, moreparticularly functional disorders with:

nasal breathing,

mastication,

swallowing,

phonation,

and consequently aimed at correcting anomalies in the shape of themouth, that is to say anomalies in the shape of the buccal osseous basesand malpositions of the teeth.

2. Background of the Related Art

In order to correct the position of the teeth in patients, it is knownpractice to employ corrective medical appliances known as "orthodonticpositioners", which in plan view adopt the shape of the U and compriseat least one upper or lower trough but normally both an upper and alower trough, each trough containing a number of depressions forreceiving and retaining the teeth held therein and returning them to aposition that is estimated as being the ideal position. There arevarious kinds of orthodontic positioner, what they have in common beingthat they have specific locations for the existing teeth and, in somecases, for the permanent teeth yet to come (see, for example, FrenchPatent No. 2329247): movements of the teeth within these orthodonticpositioners are therefore not permitted.

Devices known by the name of "channel activators" for treatment as partof dento-facial therapy are also known, from French Patent No. 2641964.

These channel activators consist, in general, of a double tray (ordouble trough) of semi-elliptical shape, the channels or troughs beingseparated by a horizontal partition (or thickness). Unlike in theaforementioned orthodontic positioners, there are no precise receivingsfor the teeth within the double channel. Indeed, the interior surface ofthe vertical or inclined walls of the double channel, among which thevestibular strip (external) and the lingual strip (internal), and thesurface of the horizontal partition, are smooth.

The basic idea underlying the channel activators described in FrenchPatent No. 2641964 is as follows: buccal deformation and theaccompanying malpositions of the teeth are due to functional disorderswith the neurovegetative functions that are: nasal breathing,mastication, swallowing and phonation. In most cases treated, thewearing of the tray activators and the exercises that accompany theirday-to-day wearing allow the four aforementioned neurovegetativefunctions to be corrected and as a consequence allow the anomalies inthe shape of the buccal osseous bases and malpositions of the teeth tobe corrected.

However, the channel activators described in French Patent No. 2641964are not entirely satisfactory as they actually present the followingdrawbacks:

in some instances it has been found, during treatment, that an incisorinfraclusion (or gap) appears. In other words, a space in the verticaldirection appears between the upper and lower incisors. Thisinfraclusion is due, in particular, to the position of the tongue, thisposition being associated with atypical swallowing of a childlike type(inserting the tongue) between the incisors at the time of swallowing;

in other instances, the transverse expansion that is sought and neededfor fitting in all the teeth is not achieved;

in the case of the treatment of certain adults, certain anomalies in theshape of the buccal osseous bases could not be corrected, such as:

a significant MDM (Maxillo-Dental Malocclusion) corresponding to teethwhich are too large compared with the size of the jaw bones [(i.e. theupper jaw (maxilla) and the lower jaw (mandible)];

an hereditary class-III anomaly (or prognathism) corresponding to aforward position of the mandible, often associated with underdevelopmentof the upper jaw bone.

An essential objective of the invention is therefore to provide asolution to the aforementioned drawbacks of the channel activatorsdescribed in French Patent No. 2641964. Another important objective ofthe invention is to provide new corrective appliances for functionaldento-facial orthopaedic treatments which are suitable for and effectivein treating children who have their deciduous or permanent incisors, aswell as adolescents and adults, in whom the risks of a relapse or of theappearance of further malpositions of the teeth in normal use of theseappliances are minimized.

SUMMARY OF THE INVENTION

To this end, the subject of the present invention is novel correctiveappliances for functional dento-facial orthopaedic treatment andperiodontics, made of a natural or synthetic flexible and food-gradematerial, consisting, in general, of a double channel (or trough), thesetwo channel externally, in a horizontal plane, adopting the shape of aflared U and being separated by a thick, slightly horizontal, partition,the interior surface of these two trays, which are defined between, onthe one hand, lateral walls, among which the vestibular strip (external)and the lingual and palatine strips or rolls (internal) and, on theother hand, the thick horizontal partition, being smooth.

The novel corrective appliances for functional dento-facial orthopaedictreatment and periodontics according to the invention are characterizedin that:

(a) that part of the tray that is intended to receive the lower incisorsis in the shape of a straight channel which opens, at its two ends, intotwo tooth channels respectively, these being intended to receiverespectively a lower canine, two lower premolars (corresponding to twomilk-tooth molars of a child) and, possibly, at least one lower molar;

(b) the length of the straight channel is designed to be long enough forthe four lower incisors to have enough space to fit in it;

(c) the depth of the straight channel is designed to completely enclosethe lower incisors and, for this purpose, the height of the lingual andvestibular side walls delimiting the straight channel from the thickhorizontal partition is at least equal to the height of the incisors upto their neck.

In an attempt at simplifying matters, the medical appliances forfunctional dento-facial orthopaedic treatment and periodontics of thepresent invention will hereafter be called "corrective appliances".

In the context of the invention:

the term "lingual (side) wall" or "lingual strip" or "lingual roll"denotes that part of the corrective appliances which runs alongside thelower teeth on the tongue side, in the region of the incisors, as wellas the canine, the premolars (or milk-tooth premolars in the case of achild) and the molars;

the term "palatine (side) wall" or "palatine strip" denotes the internalwall of the corrective appliances on the upper teeth and palate side;

the term "vestibular (side) wall" or "vestibular strip" denotes theouter wall of the corrective appliances located on the lower and upperteeth side;

the word "flexible", used to qualify the corrective appliances accordingto the invention, means that these appliances have an elastic behaviourwhen worn in the mouth and during chewing exercises performed in thecourse of treatment. Because of this elastic behaviour, the correctiveappliances according to the invention have a toning effect and stimulatethe facial and buccal muscles in the course of chewing exercises.

the quantified values given to the thickness of the vestibular, lingualand palatine side walls, quoted in what follows of the description, aremeasured slightly mid-way up these walls.

Advantageously, the corrective appliances according to the presentinvention are appliances of standardized shapes and sizes according tothe age of the patient and the anomaly (or anomalies) in shape that is(are) to be treated. They are prefabricated from a natural or syntheticmaterial that meets the requirements set down in French and Europeanstandards regarding the plastics intended for contact with food andwhich are sufficiently flexible. Furthermore, it has to be possible,with the chosen material, for the corrective appliance to be worn in themouth without any appreciable loss in effectiveness or damage to it whensubjected to chewing forces over a reasonable period of time. In thisrespect, the corrective appliances need to be replaced regularly, aboutevery two to three months, for reasons of lessening of effectiveness astheir toning effect becomes insufficient and for reasons of hygiene.Preferably, the corrective appliances according to the invention arebased on flexible rubber, preferably on vulcanized flexible rubber sothat they keep better in the mouth.

Advantageously too, the material of which the corrective appliances ofthe invention are made is flavoured like chewing gums.

A first important feature of the corrective appliances according to thepreferred embodiment of the present invention lies in the fact that thatpart of the double channel receiving the lower incisors is a straight orrectilinear channel, each end of this straight channel ending in a toothchannel intended to receive the lower canine, the two lower premolars(or the corresponding two milk-tooth molars) and, possibly, at least onelower molar. Consequently, in horizontal section, the straight toothchannel is essentially represented by two parallel straight lines.

By contrast, the channel activators described in French Patent No.2641964 have a markedly rounded shape in the region of the lowerincisors, involving a curvature of the channel that receives the lowerincisors, such that the distance separating the middle of the arc,corresponding to the intersection of a horizontal plane with thevestibular internal side wall of the channel of limited curvaturereceiving the lower incisors, and the middle of the segment of straightline passing through the ends of the arc is at least equal to 3 mm ormore.

The tooth channel receiving the lower incisors is delimited by twosmooth side walls, of vertical or inclined overall shape, which are thelower vestibular strip and the lingual strip (or roll).

The internal lingual side wall of the tooth channel receiving the lowerincisors is extended at its two ends by the internal lingual side wallsof the two tooth channels intended to receive the lower canine, the twolower premolars (or the corresponding two milk-tooth molars) andpossibly at least one lower molar, so that in horizontal section, thesethree lateral walls form a "U" with flared legs.

Advantageously, the width of the channel, which is preferably straight,in its upper part (i.e. near to the slightly horizontal thickpartition), is designed to be slightly equal to the thickness of thelower incisors in the region of the neck, in the sagittal direction(i.e. in the plane of symmetry passing through the middle of theseincisors).

Likewise, the width of the tooth channel intended to receive the upperincisors is advantageously designed, at its upper part, to be slightlyequal to the thickness of the lower incisors in the region of the neck,in the sagittal direction.

According to a second important feature of the invention, the length ofthe tooth channel receiving the lower incisors, which is preferablyrectilinear, is designed to be long enough that the four lower incisorshave enough space to fit in it:

in the case of a patient who has his deciduous lower incisors, that isto say between about the age of 3 and up to about the age of 6 or above,the length of this channel is of the order of 20 mm±2 mm;

in the case of a patient who has lost his deciduous lower incisors andhas not yet got his permanent lower incisors, the length of this channelis of the order of 22 mm±2 mm;

in the case of a patient who has got his permanent lower incisors, thatis to say generally from about the age of 6 or above, the length of thischannel is of the order of 24 mm±1 mm.

Likewise, the tooth channel intended to receive the upper incisors,which is slightly rounded, is designed to be large enough that the upperincisors have enough space to fit in it. To achieve this, that part ofthe tooth channel that is intended to receive the upper incisors ispreferably laterally delimited by a vestibular wall, somewhat verticaland slightly curved, in the transverse direction (from left to right orvice versa) and a palatine wall which overall is rounded in shape in theanterio-posterior direction (from front to back or vice versa) andslightly curved in the transverse direction.

According to a third important feature of the invention, the depth ofthe channel receiving the lower incisors, which is preferably straight,is such that this channel can surround the lower incisors, at least asfar as their neck, when worn in the mouth, with teeth clenched. Also asa preference, the depth of this channel measured from the thickhorizontal partition does not exceed the height of the lower incisorsfrom their cutting edge down to their neck. Also, the depth of the toothchannel intended to receive the upper incisors is designed to be greatenough to allow it to surround the upper incisors at least as far astheir neck, when worn in the mouth with the teeth clenched. Also as apreference, the dimensions of the tooth channel intended to receive theupper incisors are designed to allow:

the upper maxillar arch to be surrounded as far as the boundary betweenthe gum and the inner lip, without resting on the mucosa so as not toinjure them;

slight pressure to be exerted on the palate.

In the event of serious discomfort or injury when the appliance is wornin the mouth, the height of the (lower and/or upper) vestibular walland/or the height of the lingual wall and/or the height of the palatinewall may be reduced.

Furthermore, that portion of the thick horizontal partition on which thelower and upper incisors rest is designed to be planar so that all theincisors rest at the same time against the thick horizontal partitionand all receive the same stimulation.

Thanks to the very limited curvature of the tooth channel receiving thelower incisors, which is preferably straight (or rectilinear) (feature(a) of the invention) and to its dimensions designed to suit theincisors present (features (b) and (c) of the invention), the lowerincisors can no longer be rounded or vestibularized (i.e. incisors whichslope forwards): therefore, the number of incisor infraclusions observedin young patients has been considerably reduced.

Furthermore, thanks to such a tooth channel, which is preferablyrectilinear in the region of the lower incisors, the novel correctiveappliances are more effective in correcting the four neurovegetativefunctions mentioned earlier. Thus, the presence of a tooth channel,which is of very limited curvature, and preferably rectilinear in theregion of the lower incisors, allows better correction of the positionof the tongue (and therefore of swallowing) and consequently allowsbetter correction of the other neurovegetative functions and a bettercorrection of the anomalies in the shape of the buccal osseous bases andof the corresponding malpositions of the teeth.

Another advantage of the invention lies in the long-term stability ofthe corrections achieved.

With the exception of the length of the channels receiving the upper andlower incisors, the other dimensions of the corrective appliancesaccording to the invention can vary according to the age of the patientto be treated, the size of the patient's mouth and the pathology to betreated. It is thus possible to vary:

the length and depth of the tooth channels receiving the canines, thepremolars and, possibly, at least one molar;

the thicknesses of the vestibular, lingual and palatine walls, thesethicknesses advantageously being at least equal to 2 mm; the greatestthicknesses are reached by the lingual and palatine walls withcorrective appliances that are aimed at transversely expanding the jawbones;

the thickness of the horizontal partition, which is preferably greaterin the region of the incisors than the thickness of this same horizontalpartition in the region of the other teeth, this being with a view toenjoying a greater toning effect at this point and thus increasing thepressures and therefore stimulations given to the incisors. In theregion of the

Advantageously too, the material of which the corrective appliances ofthe invention are made is flavoured like chewing gums.

A first important feature of the corrective appliances according to thepresent invention lies in the fact that that part of the double trayreceiving the lower incisors is a straight or rectilinear channel, eachend of this straight channel ending in a tooth channel intended toreceive the lower canine, the two lower premolars (or the correspondingtwo milk-tooth molars) and, possibly, at least one lower molar.Consequently, in horizontal section, the straight tooth channel isessentially represented by two parallel straight lines.

By contrast, the tray activators described in French Patent No. 2641964have a markedly rounded shape in the region of the lower incisors,involving a curvature of the channel that receives the lower incisors,such that the distance separating the middle of the arc, correspondingto the intersection of a horizontal plane with the vestibular internalside wall of the channel of limited curvature receiving the lowerincisors, and the middle of the segment of straight line passing throughthe ends of the arc is at least equal to 3 mm or more.

The tooth channel receiving the lower incisors is delimited by twosmooth side walls, of vertical or inclined overall shape, which are thelower vestibular strip and the lingual strip (or roll).

The internal lingual side wall of the tooth channel receiving the lowerincisors is extended at its two ends by the internal lingual side wallsof the two tooth channels intended to receive the lower canine, the twolower premolars (or the corresponding two milk-tooth molars) andpossibly at least one lower molar, so that in horizontal section, thesethree lateral walls form a "U" with flared legs.

Advantageously, the width of the straight channel, in its upper part(i.e. near to the slightly horizontal thick partition), is designed tobe slightly equal to the thickness of the lower incisors in the regionof the neck, in the sagittal direction (i.e. in the plane of symmetrypassing through the middle of these incisors).

Likewise, the width of the tooth channel intended to receive the upperincisors is advantageously designed, at its upper part, to be slightlyequal to the thickness of the lower incisors in the region of the neck,in the sagittal direction.

According to a second important feature of the invention, the length ofthe tooth channel receiving the lower incisors is designed to be longenough that the four lower incisors have enough space to fit in it:

in the case of a patient who has his deciduous lower incisors, that isto say between about the age of 3 and up to about the age of 6 or above,the length of this channel is of the order of 20 mm±2 mm;

in the case of a patient who has lost his deciduous lower incisors andhas not yet got his permanent lower incisors, the length of this channelis of the order of 22 mm±2 mm;

in the case of a patient who has got his permanent lower incisors, thatis to say generally from about the age of 6 or above, the length of thischannel is of the order of 24 mm±1 mm.

Likewise, the tooth channel intended to receive the upper incisors,which is slightly rounded, is designed to be large enough that the upperincisors have enough space to fit in it. To achieve this, that part ofthe tooth channel that is intended to receive the upper incisors ispreferably laterally delimited by a vestibular wall, somewhat verticaland slightly curved, in the transverse direction (from left to right orvice versa) and a palatine wall which overall is rounded in shape in theanterio-posterior direction (from front to back or vice versa) andslightly curved in the transverse direction.

According to a third important feature of the invention, the depth ofthe channel receiving the lower incisors, which is straight, is suchthat this channel can surround the lower incisors, at least as far astheir neck, when worn in the mouth, with teeth clenched. Also as apreference, the depth of this channel measured from the thick horizontalpartition does not exceed the height of the lower incisors from theircutting edge down to their neck. Also, the depth of the tooth channelintended to receive the upper incisors is designed to be great enough toallow it to surround the upper incisors at least as far as their neck,when worn in the mouth with the teeth clenched. Also as a preference,the dimensions of the tooth channel intended to receive the upperincisors are designed to allow:

the upper maxillar arch to be surrounded as far as the boundary betweenthe gum and the inner lip, without resting on the mucosa so as not toinjure them;

slight pressure to be exerted on the palate.

In the event of serious discomfort or injury when the appliance is wornin the mouth, the height of the (lower and/or upper) vestibular walland/or the height of the lingual wall and/or the height of the palatinewall may be reduced.

Furthermore, that portion of the thick horizontal partition on which thelower and upper incisors rest is designed to be planar so that all theincisors rest at the same time against the thick horizontal partitionand all receive the same stimulation.

Thanks to the tooth channel receiving the lower incisors, which isstraight (or rectilinear) (feature (a) of the invention) and to itsdimensions designed to suit the incisors present (features (b) and (c)of the invention), the lower incisors can no longer be rounded orvestibularized (i.e. incisors which slope forwards): therefore, thenumber of incisor infraclusions observed in young patients has beenconsiderably reduced.

Furthermore, thanks to such a tooth channel, which is rectilinear in theregion of the lower incisors, the novel corrective appliances are moreeffective in correcting the four neurovegetative functions mentionedearlier. Thus, the presence of a tooth channel, rectilinear in theregion of the lower incisors, allows better correction of the positionof the tongue (and therefore of swallowing) and consequently allowsbetter correction of the other neurovegetative functions and a bettercorrection of the anomalies in the shape of the buccal osseous bases andof the corresponding malpositions of the teeth.

Another advantage of the invention lies in the long-term stability ofthe corrections achieved.

With the exception of the length of the channels receiving the upper andlower incisors, the other dimensions of the corrective appliancesaccording to the invention can vary according to the age of the patientto be treated, the size of the patient's mouth and the pathology to betreated. It is thus possible to vary:

the length and depth of the tooth channels receiving the canines, thepremolars and, possibly, at least one molar;

the thicknesses of the vestibular, lingual and palatine walls, thesethicknesses advantageously being at least equal to 2 mm; the greatestthicknesses are reached by the lingual and palatine walls withcorrective appliances that are aimed at transversely expanding the jawbones;

the thickness of the horizontal partition, which is preferably greaterin the region of the incisors than the thickness of this same horizontalpartition in the region of the other teeth, this being with a view toenjoying a greater toning effect at this point and thus increasing thepressures and therefore stimulations given to the incisors. In theregion of the incisors, the thickness of the horizontal partition ispreferably between 2 and 5 mm;

in general, the external dimensions of the corrective appliances.

The main action of the lingual, palatine and vestibular walls is tocorrect an inclined implantation to a slightly vertical implantation.Likewise, in the case of corrective appliances for transverse expansion,a second major action of the lingual and palatine walls is to make spaceand to part the teeth.

Advantageously, the lingual wall (or lingual roll), which corresponds tothat part of the appliance which runs alongside the lower teeth on thetongue side in the region of the incisors, as well as the canine, thepremolars and the molars is designed to be:

tall enough to cover the teeth and the alveolar bone in part withoutreaching the frenum of the tongue;

thick enough to allow, in certain instances, the transverse expansionneeded to provide space for all the teeth.

Furthermore, in order to encourage or to maintain a verticalimplantation of the lower incisors, the thickness of the lingual wall isadvantageously greater in the region of the lower incisors than it is inthe region of the other lower teeth. In general, the thickness of thelingual wall in the region of the lower incisors varies, according tothe age of the patient, between 3±1 mm and 7±1 mm, while the thicknessof the lingual wall in the region of the molars varies between 2±1 mmand 4±1 mm. Likewise, the thickness of the palatine wall in the regionof the upper incisors is greater than the thickness of the palatine wallin the region of the other teeth. In general the thickness of thepalatine wall in the region of the upper incisors varies, according tothe age of the patient, between 4±1 mm and 10±1 mm; while the thicknessof the palatine wall in the region of the molars varies between 3±1 mmand 5±1 mm.

The corrective appliances according to the invention are recommended fortreating children (from the age of about 3) as soon as they have theirmilk-tooth incisors or permanent incisors, adolescents and adults (whomay be over 50). By contrast, the positioners of the prior art cannotgenerally be envisaged until the first permanent teeth come through,namely from the age of about 6.

The functional corrective appliances according to the present inventionmake it possible to treat:

At the same time, by following the aforementioned exercises normally,the corrective appliances according to the invention make it possible,in the majority of cases, under the aforementioned provisos, graduallyto correct the four neurovegetative functions which are functionallyinterdependent and to derive the greatest benefit from the anticipatedresults.

Thus it becomes possible to correct functional disorders of theneurovegetative functions and the resulting anomalies in the shape ofthe mouth.

Finally, it is important to note that, in addition to the aforementionedadvantages, the corrective appliances according to the invention havethe advantages of the tray activators described in French Patent No.2641964 without the drawbacks mentioned earlier.

The invention will now be illustrated through three particularembodiments of the invention.

On plate 1/3, in FIGS. 1 and 2, are depicted two views from above andbelow of a corrective appliance for transverse expansion, whichappliance is intended for an adult, these two views from above and belowcorresponding respectively to the tray for the upper jaw (FIG. 1) andthe tray for the lower jaw (FIG. 2). The upper and lower trays are alsospecified by means of cross sections A-G.

On plate 2/3, in FIGS. 3 and 4, are depicted two views from above andbelow of a corrective appliance for transverse expansion, intended for achild of between about 6 and about 12, these two views from above andbelow corresponding respectively to the tray for the upper jaw (FIG. 3)and to the tray for the lower jaw (FIG. 4). The upper and lower traysare further specified by means of cross sections I-H.

On plate 3/3, in FIGS. 5 and 6, are depicted two views from above andbelow of a shaping corrective appliance, intended for an adult, thesetwo views from above and below corresponding respectively to the trayfor the upper jaw (FIG. 5) and to the tray for the lower jaw (FIG. 6).The upper and lower trays are further specified by means of crosssections I-H.

As can be seen in FIGS. 1 and 2, the corrective appliance for transverseexpansion consists of two vertical strips (1, 2) connected by a thickhorizontal partition (3). The cross sections A-G show the overall shapeof the upper and lower trays. These trays are also sized to cover themaxillar and mandibular arches as far as the neck. The rectilinear toothchannel (4) intended to receive the lower incisors is 24 mm long becausethis corrective appliance is intended for an adult.

The main action of the corrective appliance for transverse expansion isto correct an MDM.

Like all the corrective appliances according to the invention, theappliance described in plate I/3 is designed to free, incite and guidethe impulses produced by the sets of muscles. Furthermore, thisappliance is designed to increase the dimensions of the osseous bases inthe jaw bones region and, if necessary, to increase the dimensions ofthe alveoli. This appliance is also designed to allow the implantationof the teeth to be normalized, and to allow good occlusion and correctand functional dental articulation. To this end, by comparison with theshaping corrective appliance shown in FIGS. 5 and 6, this appliance ischaracterized by:

a greater thickness of the vestibular strip (of the order of 4 mm in theregion of the lower incisors and of the order of 5 mm in the region ofthe upper incisors--(see sections A and B);

far greater thickness of the lingual strip (internal) which, inaddition, is extended more downwards than in the shaping correctiveappliance for encouraging a widening of the mandible;

greater width of the tooth corridor bounded between the two (lingual andvestibular) strips, to allow centrifugal moving of the teeth.

The corrective appliance depicted in FIGS. 3 and 4 is also aimed attransverse expansion, but in patients aged from about 6 to 12. Thisappliance consists of two vertical strips (1, 2) connected by a thickhorizontal partition (3). The cross sections I-H show the overall shapeof the upper and lower channel. These two trays are dimensioned to coverthe mandibular arch as far as the neck and the maxillar arch as far asthe vestibule. The rectilinear tooth channel (4) intended to receive thelower incisors is of the order of 24 mm long if the patient has hispermanent incisors or is shorter than this (on this point, please referto the description of the invention).

This corrective appliance for transverse expansion has the same featuresas the appliance depicted in FIGS. 1 and 2, the only differences lyingin the external dimensions of the appliance and in the thicknesses ofthese walls which are smaller, to allow it to be worn in the mouth of achild 6 to 12 years old.

Depicted in FIGS. 5 and 6 is a shaping corrective appliance generallyused after a treatment using a corrective appliance for transverseexpansion. The shaping corrective appliances generally have the functionof stabilizing the corrections obtained or of reestablishing correctocclusal equilibrium, in the case of degradation of the periodontium (orpolymicrotrauma), provided that this degradation of the periodontium hasnot reached too advanced a stage.

This appliance comprises, in general, an internal vertical strip(lingual and palatine) and an external vertical strip (vestibular),these two strips being connected by a horizontal plane, i.e. the thickhorizontal partition.

As the appliance described is intended for an adult, the length of therectilinear tooth channel (4) intended to receive the lower incisors is24 mm.

The two trays of this appliance are dimensioned to cover:

the upper maxiular arch as far as the boundary between the gum and theinner lip, without resting on the mucosa in order to avoid injuringthem;

the mandibular arch as far as the neck.

Furthermore, the palatine wall advantageously extends beyond the neck ofthe teeth so as to exert slight pressure on the palate.

Of course, the invention is not restricted to the two groups ofcorrective appliances described hereinabove. In particular, it alsoencompasses:

corrective appliances for retromorphosis, intended to correct class-IIanomalies in the shape of the buccal osseous bases (mandible set backrelative to the maxilla);

functional corrective appliances for antemorphosis intended to correctclass-III anomalies in the shape of the buccal osseous bases (mandiblejutting forward relative to the maxilla), often associated withunderdevelopment of the maxilla.

What is claimed is:
 1. A corrective appliance for functionaldento-facial orthopaedic treatment and periodontics, made of a naturalor synthetic flexible and food-grade material, comprising a doublechannel, these two channels, externally, in a vertical sectional plane,adopting the shape of a flared U and being separated by a thick slightlyhorizontal partition, the interior surface of these two channels, whichare defined between lateral walls among which the vestibular strip andthe lingual and palatine strips or rolls and the thick horizontalpartition, being smooth, the corrective appliance being characterized inthat:(a) that part of the channel that is intended to receive the lowerincisors is in the shape of a straight channel which opens, at its twoends, into two tooth channels respectively, these being intended toreceive the lower teeth other than the lower incisors; (b) the length ofthe straight channel is designed to be long enough for the four lowerincisors to have enough space to fit in it, (c) the depth of thestraight channel is designed to completely enclose the lower incisorsand, for this purpose, the height of the lingual and vestibular sidewalls delimiting the straight channel from the thick horizontalpartition is at least equal to the height of the incisors up to theirneck.
 2. A corrective appliance according to claim 1, characterized inthat it comprises flexible rubber.
 3. A corrective appliance accordingto claim 2, characterized in that it comprises vulcanized flexiblerubber.
 4. A corrective appliance according to claim 1, characterized inthat the appliance is flavored.
 5. A corrective appliance according toclaim 1, characterized in that the width of the channel receiving thelower incisors, in its upper part, is designed to be slightly equal tothe thickness of the lower incisors in the sagittal direction.
 6. Acorrective appliance according to claim 1, characterized in that thelength of the tooth channel intended to receive the lower incisors issuch thatthe length of this channel is of the order of 20 mm±2 mm.
 7. Acorrective appliance according to claim 1, characterized in that part ofthe tooth channel that is intended to receive the upper incisors islaterally delimited by a slightly rounded vestibular wall portion and aplanar palatine wall portion in the region of the tooth channel.
 8. Acorrective appliance according to claim 1, characterized in that thethickness of the horizontal partition is greater in the region of theincisors than the thickness of this same horizontal partition in theregion of the other teeth.
 9. A corrective appliance according to claim8, characterized in that the thickness of the horizontal partition inthe region of the incisors varies between 2 and 5 mm.
 10. A correctiveappliance according to claim 1, characterized in that the length of thetooth channel intended to receive the lower incisors is such that thelength of this channel is of the order of 22 mm±2 mm.
 11. Correctiveappliances according to claim 1, characterized in that the length of thetooth channel intended to receive the lower incisors is such that thelength of this channel is of the order of 24 mm±1 mm.